The 2015 WHO Classification of Tumors of the Heart and Pericardium Allen Burke, MD, Fabio Tavora, MD, PhD  Journal of Thoracic Oncology  Volume 11, Issue 4, Pages 441-452 (April 2016) DOI: 10.1016/j.jtho.2015.11.009 Copyright © 2015 Terms and Conditions

Figure 1 Variations on left atrial sarcomas. (A) An entirely benign appearing area from a surgically excised left atrial mass. (B) Another area from the same tumor with myxoid mildly pleomorphic tumor cells, classified as myxofibrosarcoma by current World Health Organization guidelines. (C) A metastatic deposit in the iliac bone that occurred 1.5 years later; note similar appearance to the tumor (from the same patient) in B. The coarse capillary pattern is somewhat reminiscent of myxofibrosarcoma of soft tissue. (D) A different left atrial sarcoma, open biopsy. There is significant atypia, but no myxoid change in this area. The tumor by imaging was invading through the atrial wall (not shown). Amplification of the MDM2 proto-oncogene, E3 ubiquitin protein ligase gene (MDM2) was not present. Despite the relative lack of pleomorphism, the best classification by current World Health Organization criteria is undifferentiated pleomorphic sarcoma. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 2 Osteosarcoma, left atrium. (A) Autopsy specimen (cut open, four-chamber view) shows an infiltrative, pale and gritty mass (asterisk) centered in the left atrium with contiguous mitral valve invasion (arrow). (B) Some areas were myxoid and relatively bland, similar to myxofibrosarcoma. (C) The bone formation in this invasive area of tumor (into the pulmonary vein) showed well-differentiated osteoid. (D) In some areas, there is chondrosarcoma. (E) Other areas show poorly differentiated osteosarcoma. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 3 Left ventricular fibroma in an asymptomatic middle-aged male. (A) Contrast-enhanced electrocardiography-gated cardiac computed tomography image demonstrates an oblong, homogeneous soft-tissue mass (arrows) in the lateral left ventricle that is partly surrounded by epicardial fat. (B) Axial magnetic resonance image (double inversion recovery) confirms an oblong, hypointense mass (arrows) associated with the left ventricular wall that is partly outlined by epicardial fat (middle). (C) Gross photo of a ventricular fibroma (cut section) reveals firm, whorled white tissue (right). (D) Histologic section shows a bland spindle cell tumor with background fibrous tissue. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 4 Papillary fibroelastoma. (A) An elderly with recent cognitive decline and multiple lacunar infarcts on the magnetic resonance image. Contrast-enhanced electrocardiography-gated cardiac computed tomography image, sagittal plane reconstruction shows a 1.3 cm papillary lesion (arrow) connected to the left aortic valve by a narrow stalk. (B) Contrast-enhanced electrocardiography-gated cardiac computed tomography image reconstructed through the aortic valve plane shows proximity of the lesion (arrow) to the left main coronary ostium (arrowhead). Gross resected specimen (C) and histologic section (D) reveal multiple papillary fronds arising from a central stalk. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 5 Left atrial myxoma presenting as cerebral infarct in a 44-year-old male. (A) Contrast-enhanced electrocardiography-gated cardiac computed tomography image reconstructed at 78% of the R-R interval shows a faintly enhancing intracavitary mass (asterisk) with frond-like contour and unusual adherence to the left atrial posterior wall. (B) Specimen photograph of a myxoma demonstrates similar frond like morphology, predisposing to systemic embolization. (C) Histologic low magnification shows irregular tumor outline. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 6 Angiosarcoma in a 35-year-old female. (A) Contrast-enhanced axial computed tomography scan (soft-tissue window) shows a heterogeneously enhancing mass (arrows) filling the right atrial chamber. (B) Coronal T1-weighted magnetic resonance image (black blood) demonstrates multiple areas of high signal intensity within the mass (arrows) that is consistent with hemorrhagic foci. (C) Gross specimen photograph shows the mass (arrows) in the identical orientation to the middle figure. There are several areas of purple hemorrhagic material within the tumor and within pericardial metastatic deposits (arrowheads). (D) Histologic sections shows vasoformative areas (right) and more spindled areas (left). Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 7 Inflammatory myofibroblastic tumor. Histologically, these may resemble sarcomas or occasionally myxomas. (A) The typical low magnification shows a filiform tumor. (B) Despite the high cellularity, there are few if any mitotic figures, and there is generally a sparse inflammatory background. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions

Figure 8 Hemangioma. (A) Low magnification demonstrating attachment along the surface of the tricuspid valve (TV). The low magnification with myxoid background suggests a myxoma, which rarely if ever occurs on valves. (B) High magnification demonstrates well-formed vessels typical of hemangioma. Journal of Thoracic Oncology 2016 11, 441-452DOI: (10.1016/j.jtho.2015.11.009) Copyright © 2015 Terms and Conditions